MIL-STD-2199 Coverings For Waterborne Main Propulsion Shafting On U.S. Naval Surface Ships And SubmarinesThis standard covers standard practices for the application of a four-layer shaft covering system on the body areas of waterborne main propulsion shafting. Material and application requirements are also provided for coatings that are to be applied to waterborne shaft flange assemblies.

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MIL-STD-2199A APPENDIX A

COATING

FIGURE A-8. Schematic showing the elastomeric coating (the entire shaft and sleeve end are covered).

k. The second coat is applied over the first. The second layer is identical in chemical composition to the first except the pigment color, which is black. A different pigment color facilitates complete coverage of the second coat. Verify that the components to be charged to the reaction spray reservoirs are labeled as:

Propeller Shaft Covering System

Second Layer (Coating)

Second Coat (Black)

Part A

Propeller Shaft Covering System

Second Layer (Coating)

Second Coat (Black)

Part B

l. After the coating is tack free it shall be spark tested. If there are any areas that spark, a small quantity shall be removed from the A and B reservoirs of the plural component spray equipment, mixed in the proper ratio, and applied to the areas with a paint brush. Following cure, the areas shall be spark tested again. Continue to brush coating onto the suspect areas and repeat spark test until a satisfactory spark test is achieved.

m. Allow a minimum of 8 hours prior to wrapping the shaft section with GRP. The coating shall be tack-free prior to wrapping. VPI paper is not required, but the shaft shall be wrapped in plastic or other clean material if the shaft section is moved to a distant facility. The purpose of the wrap is to prevent coating abrasion during the move to the machine shop.

A.3.2.3 Third layer - sealing/fairing compound application. The polysulfide sealing/fairing compound shall be used to fair the shaft to the sleeve. No other fairing compound shall be permitted. Application of the sealant shall

be as follows:

a. Apply sealant only to the sleeve ends and shafting adjacent to the sleeve ends.

WARNING: The two sealant components shall not be mixed together until immediately prior to use, since the mixture will have a limited working life.

b. Completely mix the kit of sealant, or prepare a sufficient quantity from a larger kit, as shown on figure A-9. See 5.3.3 for guidance on sealant quantity per sleeve end. The two components shall be prepared as per the manufacturer's technical data sheets.